Thrym was a titan,[2] worshiped by the frost giants[1][2][3][4] as the giant god of cold and ice.[5][6] He was the de facto leader of the frost giants as well.[1][5] Thrym ruled the realm of Fimbulwinter in the Elemental Chaos, described as a large, desolate tundra accented by sparkling frozen waterfalls. His stronghold and feast hall was called Nyfholl.[2] In earlier cosmological models his realm was described as mountainous but still filled with snow, ice, frost, and glaciers.[7]

Thrym could breathe a devastating cone of cold out to 100 ft (30 m) and was completely immune to cold- or ice-based attacks. Only highly magical weapons could even touch him enough to injure him. He often granted frost giants the ability to use arcane magic equivalent to a 12th-level wizard.[5]